As an example of a cable or the like protection and guide device, for example as shown in FIG. 11, there is conventionally known a guide and support chain, having synthetic resin link bodies in which connecting rods are laterally bridged at an upper edge and a lower edge of a pair of right and left side plates 510, 510, in which the side plates 510, 510 of the link bodies are rotatably connected to each other on the front and rear sides through a connecting pin 520 and a pin connecting hole 530 while they are overlapped in the plate thickness direction, an accommodating space for a cable or the like is formed in a plurality of connected link bodies and the front and rear link bodies can be mutually changed in their forms from the linear position mode to the bending position mode or from the bending position mode to the linear position mode (refer to Patent Reference 1).
Particularly, in such a guide and support chain, a linear position maintaining stopper 541 and a linear position maintaining stopper 542, which maintain the linear position mode of link bodies are formed on one of side plates 510 connected on the front and rear sides, and a linear position maintaining stopper 551, which abuts on said linear position maintaining stopper 541, and a linear position maintaining stopper 552, which abuts on said linear position maintaining stopper 542, are formed on the other side plate 510 connected on the front and rear sides. Further, on one side plate 510 is formed an opposite surface of the linear position limiting stopper 541, which limits the bending position mode of the link bodies, and on the other side plate 510 is formed a bending position limiting stopper surface 560, which abuts on the opposite surface of the linear position limiting stopper 541.
And such a guide and support chain resists against a load of bending stress F, which is generated during maintaining the linear position mode in abutting conditions between the linear position maintaining stoppers 541, 542 and the linear position maintaining stoppers 551, 552, respectively and in slack-fitted conditions between the connecting pin 520 and the connecting hole 530, that is in three-points supporting conditions. Further, the guide and support chain resists against an excessive bending movement, which is liable to occur, in abutting conditions between the opposite surface of the linear position maintaining stopper 541 and the bending position limiting stopper 560 and in slack-fitted conditions between the connecting pin 520 and the connecting hole 530, that is in two-points supporting conditions.
Patent Reference 1: Specification of Japanese Patent No. 3157491 (on page 1, FIG. 2).
Problems to be Solved by the Invention
However, in the conventional protection and guide chain disclosed in the above-mentioned specification of Japanese patent No. 3157491, the linear position mode is maintained in three-points supporting conditions and the bending position mode is maintained in two-points supporting conditions. Thus, between the connecting pin 520 and the pin connecting hole 530 is generated an excess load for maintaining position except for rotation, which is sufficient if only a connecting function and a bending rotation function of the adjacent link bodies are exerted. Accordingly, the conventional guide and support chain is easy to wear at an early stage. When wear between the connecting pin 520 and the pin connecting hole 530 advances, not only the linear position mode of the adjacent link bodies cannot be reliably maintained without backlash, but also a form of the adjacent link bodies cannot be smoothly changed from a linear position mode to a bending position mode or from a bending position mode to a linear position mode. Further, endurance due to the connecting pin 520 and the pin connecting hole 530 cannot be sufficiently ensured.
Accordingly, problems to be solved by the invention that is the objects of the present invention are to solve the prior art problems and is to provide a cable or the like protection and guide device, which reliably maintains linear position mode of the adjacent connecting link bodies without backlash to remove distortion and can attain a smooth change of form between the linear position mode and the bending position mode, and also can exert endurance due to the connecting pin and the pin connecting hole for a long period of time.
Means for Solving the Problems
The invention according to claim 1 solves the above-mentioned problems by a cable or the like protection and guide device having a number of link bodies in each of which connecting rods are provided in a laterally bridged manner, at an upper edge portion and a lower edge portion of a pair of the right and left side plates, in which a position limiting concave portion provided on one of side plates which connects said link plate on the front and rear sides together with each other and a position limiting convex portion provided on the other side plates are rotatably connected between a linear position mode and a bending position mode through a connecting pin, which is a bending center point in an overlapped manner in the plate thickness direction, and a cable or the like is protected and guided in a cable or the like accommodating space formed in the connected plural link bodies, characterized in that the position limiting concave portion of said side plate includes a pair of abutting surfaces disposed in parallel with a reference line passing through the bending center points of the connecting pins disposed on the front and rear sides of said link body, the position limiting convex portion of said side plate includes a pair of linear position limiting surfaces disposed in parallel with each other in a plane symmetry with respect to said bending center point, and the linear position mode of said link bodies is maintained by surface contact conditions where said abutting surface and said linear position limiting surface are opposed to each other.
And the cable or the like protection and guide device according to claim 2 further solves the above-mentioned problems by, in addition to the configuration of the invention according to claim 1, that said position limiting convex portion includes a bending position limiting surface which is inclined in accordance with a largest bending angle of the link body with respect to said linear position limiting surface.
Further, the cable or the like protection and guide device according to claim 3 further solves the above-mentioned problems by, in addition to the configuration of the invention according to claim 2, that said linear position are continuously formed through an arc plane whose radius is a minimum distance from said bending center point to said abutting surface.
It is noted that the connecting pin in the present invention may be provided in any one of the position limiting concave portion and the position limiting convex portion in the longitudinal direction of the side plate. Even if the connecting pin is provided in any one of them, a basic action and effect are not different from each other.